Learning Experience

Science Concepts

Learning Activities

Course Introduction

1. Stalking Nature’s Pharmacy: The Search for Medicinal Plants

Characteristics of life, plants in everyday life, nature of science and scientific investigations

Students consider the various roles plants play in their everyday lives and read about the ethnobotanist Mark Plotkin and his quest for medicinal plants; students carry out an experiment to investigate the potential of certain herbs and spices in treating microbial infections and then construct an argument based on their findings and readings about the promise of medicinal plants.

Unit 1: Exploring Resources, Dynamics, and Diversity in Ecosystems

2. Simple Change, Unintended Consequences: Ecosystems

Connections among biological, physical, and chemical processes; how interactions among the biotic components and between the biotic and abiotic component define the features of an ecosystem; dynamic equilibrium in ecosystems; impact of change in ecosystems

Students examine the impact of a seemingly small change on the ecosystem of Lake Victoria; to learn about ecosystems, students first characterize and analyze soil and water samples as ecosystems and read about dynamic equilibrium in ecosystems; they then analyze the impact of a natural or human-made change in the ecosystem on the biological, chemical and physical components and their interrelationships.

Further Investigation—
Changes in the Neighborhood: Ecological Succession

Factors involved in ecological succession

Students read about the impact the eruption of Krakatau had on the surrounding ecosystems; students explore ecological succession directly by investigating milk as it undergoes successive changes; they then apply their understandings to explaining ecological succession in the recovery of Krakatoa.

3. So Many Species, So Much Time: The Origins of Biodiversity

Nature of biomes, definition of species, origins of biodiversity, natural selection, vertical and divergent evolution

Students analyze patterns in the distribution of species around the world and identify factors in the environment that determine the amount of biodiversity in an ecosystem; students identify criteria that define a species using the results of an activity and a reading by E.O. Wilson; students model natural selection using different implements to pick up different foods, explain observations about finch evolution in the Galapagos Islands, and are challenged to explain the enormous diversity observed in the cichlids of Lake Victoria.

4. Go Forth and Populate: Population Dynamics

Communities and populations in ecosystems, population interactions and resource use, carrying capacity and limiting factors, patterns of population growth, biotic potential

Students calculate an ecological footprint for a fictional person and then read about the possibility of a population crisis in the future; they construct growth curves for a model rabbit population, identify factors that affect the population growth using a model system of a rabbit population, and consider how carrying capacity determines the growth of populations; they then apply their understandings about factors that affect the population growth to decide whether Earth can sustain a population of 9.5 billion people.

5. Cycling Through the Ecosystem: The Movement of Matter and Energy in Ecosystems

Interdependence of organisms, flow of energy in ecosystems, trophic levels, role of decomposers, biogeochemical cycles, recycling of matter through ecosystems and through organisms

Students read about biomes and biogeochemical cycles, develop a presentation and present their cycle to the class in a jigsaw learning activity. Students consider the foods they eat, the functions the foods have in their survival, and the need to recycle elements; students explore how energy flows through an ecosystem and explain the transfer of energy at each step; they then explore the cycling of matter in biogeochemical cycles and apply their understanding of the movement of energy and matter in ecosystems to designing a lunar biosphere that can sustain life for two years.

Unit 2: Exploring Metabolism, Enzymes, and Their Place in the Cell

6. Corn to Milk: Metabolic Pathways

Universality of biomolecules and their functions, catabolic and anabolic pathways, metabolism as an indicator of common ancestry

Students learn about biomolecules in a jigsaw learning experience; students conduct a chemical analysis to compare the biomolecules found in corn and milk; they then trace carbon atoms from starch molecules in corn to lactose in milk and read about the chemical reactions involved in capturing energy, in the breakdown of nutrients, and in the biosynthesis of new biomolecules from these building blocks; students then trace a food item that they consumed through their own metabolic pathways.

7. Pernicious Poisons: Enzymes in Metabolic Pathways

Structure, function, and mechanisms of action of enzymes; role of enzymes in metabolic pathways

Students observe a demonstration of enzyme action and explore the mechanisms. They then determine the consequences to an organism if a specific metabolic pathway is blocked by an enzyme inhibitor.

8. Cell—At the Center of Excellence: Cell Structure and Function

The importance of being cellular, cell structure (including membranes) and function, cell specialization, differences between prokaryotes and eukaryotes

Students read about scientists who are trying to create a living cell and discuss why they think scientists might want to "build a cell in a test tube"; students then build a model of a cell, and describe the relationships between metabolic functions and cellular components.

9. The Unsolved Mystery: Origins of Life

Scientific theories about the origins of biomolecules, their coalescence, and the formation into cells

Students create a timeline depicting the history of Earth; they identify the components needed to create the first biomolecules; they then develop their own theories of how life started, and compare their theories to those proposed by scientists.

Course Conclusion

10. Final Challenge: Reaping From Nature’s Pharmacy

Applying concepts in ecology, evolution, and cell biology

Students select a drug or pharmaceutical product from a plant or other organism and research its place in the ecosystem, its likely origins in that ecosystem, and its mechanism of action at the cellular level.

Learning Experience

Science Concepts

Learning Activities

Course Introduction

1. DNA—The Master Molecule: The Nature of the Genetic Material

DNA structure and function,; DNA replication; history of the discovery of DNA as the genetic material, science as a human endeavor, the nature of scientific research

Students role play scientists whose research contributed to the understanding of the structure and function of DNA; students build a model of DNA and use it to learn about DNA replication.

Further Investigation—
The Goop of Life: Isolating DNA

DNA as a biological molecule with specific properties that are similar in all organisms, universal nature of biomolecules and cell structure

Students isolate DNA from various organisms, describe its properties, and discuss the evolutionary implications of DNA as the genetic material.

Unit 1: Exploring the Transfer of Information from DNA to Protein to Trait

2. Translating Information into Action: Information Transfer for DNA to Protein

Nature of a gene, transcription, translation, protein structure, mutations, relationship between changes in DNA sequence and changes in traits

Students read about a scientist’s plan to use DNA as a way of sending secret messages; students decode the language of DNA, and model transcription and translation; students explain how information moves from DNA to proteins to traits, and analyze the impact of mutations on proteins and traits. Students use their understandings to explain Griffith’s classic experiment.

3. Of Proteins and Traits: The Molecular Basis of Traits

Relationships among DNA, protein, and traits; biochemical basis of traits; making genetically modified organisms

Students read about genetically modified organisms and conduct an experiment in which they insert of new gene into bacteria, giving the bacteria a new trait; students learn how new traits are inserted into plants and then decide whether they would eat a potato with a gene from a different organism, using evidence to explain their decision.

4. Home on the Chromosome: The Structure and Function of Chromosomes

Chromosome structure, chromosomes as the genetic legacy, meiosis and gamete formation;, recombination, the origins of trait variation, karyotypes

Students assume the role of genetic counselors and analyze karyotypes for a couple expecting a baby; students build a model of a chromosome and then model gamete formation and meiosis; students explain how mistakes can occur during meiosis and the consequences of those mistakes.

Unit 2: Exploring Patterns of Inheritance

5. The Sickling Cell: A Dominant and Recessive Trait

Dominance and recessiveness, homozygosity and heterozygosity, relationship between genotype and phenotype

Students read about sickle cell disease, use data to explain the biochemical and molecular basis of the disease, and explore patterns of inheritance; students explain why, from an evolutionary perspective, a mutated gene might be retained in a population.

6. Return of Martin Guerre: Simple Inheritance Patterns

Mendelian genetics, patterns of inheritance, Punnett squares, cross-over predicting and explaining variations in offspring, DNA analysis and RFLPs

Students read about a man returning to a village claiming an identity; students analyze Mendel’s data and determine how variation can occur using chromosome models; students analyze molecular genetic data and patterns of inheritance to determine the man’s true identity.

7. So Many Traits; So Few Genes: Non-Mendelian Traits

Non-Mendelian patterns of gene expression; one gene-more than one protein principle; role of environment in trait variation

Students consider patterns of height variation in their class and speculate how this might occur; students read descriptions of various traits and identify the non-Mendelian mode demonstrated; students apply their understanding of non-Mendelian traits to the trait of height.

Further Investigation—There’s More to Life than Sequences: Epigenetics

Epigenetics: the effect of environment on gene expression

Students read about changes that occur in identical twins as they age. Students build a model of chromatin and investigate how methylation affects gene expression. Students use their understandings about epigenetics and the effects of environment to explain changes in gene expression.

Unit 3: Exploring the Evidence for Evolution

8. Creatures of the Future: Basic Principles of Evolution

Meaning of theory in science; fundamentals of evolution; evolution, past, present and future; environmental influences on evolution

Students review their prior knowledge about evolution and then discuss the word “theory” in science. They are challenged to describe what their neighborhood might look like in 50 million years and describe the evolution of a single organism in this time. They create an evolutionary timeline, read about whale evolution, and analyze theories of how life began.

9. Marvelous Blunders: Revisiting Natural Selection

Mechanism of natural selection, role of variation in populations, changes in the gene pool of a species as the basis for all evolutionary changes

Students read about mutating bacteria as a world health crisis; students conduct an experiment to determine how bacteria develop antibiotic resistance and discuss how the development of resistant strains of bacteria is the result of natural selection; students discuss the importance of understanding evolution to life in the modern world.

10. Ancient Genes, Age Old Processes: Molecular Evidence for Evolution

The nature of scientific evidence; similarities and differences among the biochemical and molecular structures and functions of organisms; relationships between molecular and anatomical evidence for evolution

Students identify similarities among seemingly very diverse organisms, interpret an experiment, and analyze data relating to gene homologies among different organisms; students are challenged to create a model of evolution that accounts for the molecular and anatomical evidence; students determine how cladograms can provide information about the relatedness of organisms.

11. Fishing Expedition: Anatomical and Fossil Evidence for Evolution

Anatomical homologies; nature of fossils and the significance of fossil evidence; transitional organisms.

Students take on the role of paleontologists looking for transition animals between fish and amphibians; students make predictions about what to look for and where based on their understanding of evolution; students revise their model of evolution based on their new evidence and understandings.

Course Conclusion

12. Designing a Solution to a Biological Problem

Using scientific concepts and their application to solve human problems

Students use their understandings about cells, genetics, and ecosystems to design an approach to solving a human problem; students compare their approach with the approach used in the learning experiences by writing a story, designing an investigation, and creating a process for sharing and discussing findings.